/*
 * Copyright (c) 2008, 2016, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the Classpath exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package org.openjdk.btrace.instr;

import static org.objectweb.asm.Opcodes.ATHROW;
import static org.openjdk.btrace.instr.Constants.THROWABLE_INTERNAL;
import static org.openjdk.btrace.instr.Constants.THROWABLE_TYPE;

import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;

/**
 * This visitor helps in inserting code whenever a method "returns" because of an exception (i.e.,
 * no exception handler in the method and so it's frame poped). The code to insert on method error
 * return may be decided by derived class. By default, this class inserts code to print message to
 * say "no handler here".
 *
 * @author A. Sundararajan
 */
public class ErrorReturnInstrumentor extends MethodReturnInstrumentor {
  private final Label start = new Label();
  private final Label end = new Label();

  public ErrorReturnInstrumentor(
      ClassLoader cl,
      MethodVisitor mv,
      MethodInstrumentorHelper mHelper,
      String parentClz,
      String superClz,
      int access,
      String name,
      String desc) {
    super(cl, mv, mHelper, parentClz, superClz, access, name, desc);
  }

  @Override
  protected void visitMethodPrologue() {
    addTryCatchHandler(start, end);
    visitLabel(start);
    super.visitMethodPrologue();
  }

  @Override
  public void visitMaxs(int maxStack, int maxLocals) {
    visitTryCatchBlock(start, end, end, THROWABLE_INTERNAL);
    visitLabel(end);
    insertFrameReplaceStack(end, THROWABLE_TYPE);
    onErrorReturn();
    visitInsn(ATHROW);
    super.visitMaxs(maxStack, maxLocals);
  }

  @Override
  protected void onMethodEntry() {}

  @Override
  protected void onMethodReturn(int opcode) {}

  protected void onErrorReturn() {
    asm.println("error return from " + getName() + getDescriptor());
  }
}
